The requirements for materials that are used in modern aircraft construction are continually increasing as a result of ever new regulations and changing requirements for the aircraft. For example, the requirements that an aircraft has to meet after a crash landing in which a fire breaks out, known as a post-crash fire, are becoming more stringent as a result of new regulations. The occupants must be protected from the flames attacking from the outside for a predetermined period of time that is sufficient to allow the passenger compartment to be evacuated.
The improved protection of the passenger compartment may be obtained by reinforcing the fuselage and also the secondary structure. However, this usually entails an increase in weight. However, a weight increase is undesired, in particular in the case of aircraft construction. Especially the hold in the lower region of an aircraft, produced from lightweight materials such as glass fibers and phenolic resins, offers only little protection to flames attacking from the outside. In order to improve the protection of the passenger compartment here, additional fireproof bulkheads can be introduced. These fireproof bulkheads are fitted between the lower region of the passenger compartment and the hold.
However, fireproof bulkheads that are to be fitted in this region have to meet special requirements. On the one hand, they must provide effective protection of the passenger compartment in the event of a fire. On the other hand, the free circulation of air around the hold must be ensured. This is necessary in particular when there is a sudden drop in pressure in the aircraft. If a high circulation of air cannot be ensured, there is the risk of the aircraft being torn apart if there is a sudden drop in pressure caused by damage to the outer skin of the aircraft, due to the great differences in pressure that cannot be equalized quickly enough.
The structures used until now as fireproof bulkheads in the aircraft substantially comprise mechanical flap structures, which close in the event of a fire, or deflector plates arranged in the form of a cascade.
Of these, flap structures have the disadvantage that, in the case of complicated geometries, they can only be realized with difficulty and, moreover, are accompanied by high weight and, on account of their mechanics, are susceptible to malfunctions or failures.
Deflector plates arranged in the form of a cascade have the disadvantage that they cannot completely separate the different regions.
A construction which normally ensures a high level of air permeability but at the same time can serve effectively as a fireproof bulkhead in the event of a fire, and along with that achieves a low weight, cannot be provided by either of the two types of fireproof bulkhead used so far in aircraft construction.